G56 The Structure of the Horse's Foot and Principles of Shoeing. 
theories wliicli will not stand the test of common sense, and will 
rather hinder than assist him in deciding what plan of shoeing 
is the least open to objection. 
Taking the foot as a whole, it is evident that it is so formed 
that it can support the animal's weight, at the same time that its 
various parts yield under pressure just enough to avoid con- 
cussion. The hoof is produced as fast as the wear and tear, under 
natural conditions, make new material necessary. So long as 
the horse is left to take care of himself and his feet, all goes well ; 
but when man sets his needs in place of the animal's instincts, 
things commonly go wrong, and the hoof among other parts 
gives way. 
The first and most important function of the foot then is to keep 
itself in repair, a work which it performs well within certain limits. 
Next, the hoof horn is wanted to protect the internal sensitive 
structures by which it is formed, just as the outer or scarf skin 
covers and protects the true skin. The scales, which are the 
elements of the outer skin, and hair become crowded together to 
form the hoof, Avhich is really amass of hairs glued together, and 
it adds to toughness and density a fair degree of elasticity. 
Perhaps if we had contrived to use our horses with such care 
that shoes would not have been required, we might by this time 
have been in possession of a race of tough-hoofed horses, for which 
the services of the shoeing-smith would not have been wanted. 
Lastly, the function of the foot is to afford the horse a firm 
support and secure hold of the ground at all paces. That the 
hoof yields under pi-essure is admitted. That it spreads out, as 
some people contend, when it is placed on the ground, is denied 
by all who have carefully looked at the arrangement of the parts 
of the organ in their relation to each other. The suggestion that 
the foot expands so much that the shoe ought to have a hinge at 
the toe to allow the movement to go on without hindrance is 
not worth discussion, nor, indeed, is any point connected with 
the theory of gi'ound surface expansion and the tendency of the 
concave sole to assume the form of a plane under the pressure 
of the animal's weight. 
The whole theory, in fact, may simply be left to the ingenious 
persons who are fond of splitting straws. The practical man 
need not be concerned about such matters. His own common 
sense will teach him that the base of a horse's foot cannot 
expand, nor the sole descend to any extent without tearing the 
inside of the hoof from the internal foot to which it is every- 
where closely and securely attached. 
When the sole does descend it is the result of disease, and 
then it does not ascend again, but remains in its distorted state, 
